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Renesas 71V3557S85BG8
- Part No.:
- 71V3557S85BG8
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 119-BGA
- Datasheet:
-
71V3557S85BG8.pdf
- Description:
- IC SRAM 4.5MBIT PARALLEL 119PBGA
- Quantity:
- Payment:
- Shipping:
Inventory:1,643
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Product details
Overview
71V3557S85BG8 from Integrated Device Technology is a 128K × 36-bit (4.5 Mbit), 3.3V synchronous ZBT™ SRAM with flow-through outputs, 100 MHz operation (7.5 ns clock-to-data access), and burst counter support. It features zero bus turnaround for seamless read/write transitions and is used in high-speed packet buffering, network switch fabric control tables, and cache coherency logic.
For engineers reviewing the 71V3557S85BG8 datasheet, 71V3557S85BG8 pinout, 71V3557S85BG8 application, or 71V3557S85BG8 equivalent, key selection criteria include ZBT™ timing compliance, 100-pin TQFP mechanical compatibility, JTAG boundary-scan support, and linear/interleaved burst mode configurability via LBO.
Technical Context
The 71V3557S85BG8 implements a synchronous dual-edge-triggered address/control register architecture with flow-through output path-no output register-enabling deterministic 1-cycle latency from CLK rise to valid data. Its burst counter advances on ADV/LD = HIGH and supports four-word sequences defined by static LBO polarity.
Three chip enables (CE1, CE2, CE2) provide flexible depth expansion; CEN suspends all synchronous operation without affecting output state; ZZ enables low-power sleep mode with guaranteed data retention. The device integrates IEEE 1149.1-compliant JTAG test circuitry with optional TRST.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 128K × 36-bit (4.5 Mbit); supports 256K × 18-bit via pin-compatible variant |
| Clock Frequency | 100 MHz maximum; enables 10 ns cycle time for high-throughput memory access |
| Access Time | 7.5 ns clock-to-data (tCD); defines minimum latency from CLK edge to valid I/O output |
| Supply Voltage | VDD = 3.3 V ±5% (core), VDDQ = 3.3 V ±5% (I/O); separate power domains reduce noise coupling |
| Burst Length | Fixed 4-word burst; sequence order (linear/interleaved) selected by LBO pin level |
| Byte Write Control | Four independent active-low BW1–BW4 signals enable per-9-bit-byte write masking |
| Operating Temperature | –40°C to +85°C industrial range; validated for embedded telecom and industrial control environments |
Pinout & Package
71V3557S85BG8 is packaged in a JEDEC-standard 100-pin thin quad flatpack (TQFP), 14 mm × 20 mm body, 0.5 mm pitch. Pin 1 is located at top-left corner (notch-marked side), with pins numbered counter-clockwise.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | Synchronous inputs latched on rising CLK edge when ADV/LD = LOW and chip enabled |
| CE1, CE2, CE2 | Chip Enables | CE1/CE2 active-low; CE2 active-high; any deassertion initiates one-cycle deselect and I/O tri-state |
| R/W | Read/Write Control | Synchronous signal defining load-cycle access type; determines burst direction after initial address load |
| ADV/LD | Advance / Load Control | LOW loads new external address; HIGH increments internal burst counter; sampled synchronously |
| LBO | Burst Order Select | Static input: LOW = linear burst, HIGH = interleaved burst; must remain stable during operation |
| CLK | System Clock Input | Rising-edge-triggered master timing reference; all synchronous inputs referenced to this edge |
| I/O0–I/O31, I/OP1–I/OP4 | Data I/O Bus | 36-bit bidirectional flow-through path; no output register; OE controls asynchronous tri-state |
| ZZ | Sleep Mode Enable | Active-high synchronous input that gates internal clock and reduces power while retaining data |
Key Features
| Feature | Design Value |
|---|---|
| ZBT™ Zero Bus Turnaround | Eliminates dead cycles between consecutive reads/writes-critical for pipelined bus protocols like PCI-X and RapidIO |
| Flow-Through Output Architecture | Removes output register delay, enabling deterministic 1-cycle data delivery from CLK edge to I/O pins |
| Configurable 4-Word Burst | Linear or interleaved addressing via LBO pin-matches CPU cache line fetch patterns or DSP DMA requirements |
| Individual Byte Write (BW1–BW4) | Enables precise 9-bit subword writes without read-modify-write; essential for protocol header updates and status flags |
| JTAG Boundary Scan (IEEE 1149.1) | Integrated TAP controller with TDI/TDO/TCK/TMS/TRST supports production test and board-level diagnostics |
| Three Independent Chip Enables | Allows seamless depth expansion across multiple devices without external logic or address decoding overhead |
Applications
| Network Packet Buffering | Switch Fabric Control Tables |
|---|---|
|
Use Scenario: Storing ingress/egress packet headers and metadata in Layer 2/3 switches with strict latency budgets. IC Role / Device Role / Timing Role: High-speed, low-latency buffer memory interfacing directly to SERDES MAC controllers. Use Value: 7.5 ns tCD and ZBT™ operation ensure sub-10 ns read-to-read turnaround-meeting 10 Gbps line-rate forwarding requirements. |
Use Scenario: Holding forwarding database entries (FDB), VLAN mapping tables, and QoS policy rules in modular chassis switches. IC Role / Device Role / Timing Role: Synchronous SRAM serving as lookup table memory for TCAM-assisted match engines. Use Value: 100 MHz clock rate and 4-word burst support accelerate parallel table walks, reducing average lookup latency by 30% vs. async SRAM. |
| Cache Coherency Logic | DSP Data Buffers |
|
Use Scenario: Implementing directory-based cache coherency state tracking in multi-core SoC interconnects. IC Role / Device Role / Timing Role: Shared memory node storing MESI/MOESI state bits and owner ID for cache lines. Use Value: Flow-through outputs and zero-turnaround guarantee deterministic response timing for snoop request arbitration. |
Use Scenario: Providing real-time data buffers for FFT, FIR, and channel estimation algorithms in wireless baseband processors. IC Role / Device Role / Timing Role: Dual-port-capable memory accessed concurrently by DSP core and DMA engine. Use Value: Linear burst mode aligns with DSP's natural 64-byte cache line size, improving DMA throughput by 25% over random access. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C1355BV18-100BZI | 128K × 36-bit, 100 MHz, but uses 165-ball fBGA only; no TQFP option; lacks JTAG | Targeted at space-constrained BGA-only designs; unsuitable for TQFP-reliant legacy layouts | Select if board uses fine-pitch BGA and JTAG is not required; verify thermal pad layout compatibility |
| AS7C3256B-10JIN | 128K × 32-bit (not 36-bit); 10 ns access; no burst counter or ZBT™; commercial temp only (0°C to +70°C) | Lower-cost alternative for non-critical, non-bursting applications where byte parity is not needed | Use only in cost-sensitive, non-industrial designs where 4-bit width reduction and missing ZBT™ are acceptable |
Compared with CY7C1355BV18-100BZI and AS7C3256B-10JIN, the 71V3557S85BG8 uniquely delivers TQFP packaging, integrated JTAG, industrial temperature rating, and true ZBT™ timing-making it the sole choice for upgradeable, testable, and thermally robust high-speed buffering.
Availability
71V3557S85BG8 is available at Aetrix Electronics and suitable for network infrastructure, industrial automation, and aerospace avionics requiring stable component supply across extended product lifecycles.
Supply support for 71V3557S85BG8 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor solutions for communications and computing markets.
The 71V3557S85BG8 belongs to IDT's ZBT™ SRAM product line, engineered specifically for high-bandwidth, low-latency data buffering in packet-switched networks and real-time embedded systems.
FAQ
What does the 'S85BG8' suffix indicate in 71V3557S85BG8?
The 'S85BG8' suffix denotes a specific configuration: 'S' = standard speed grade (100 MHz), '85' = industrial temperature range (–40°C to +85°C), 'B' = 100-pin TQFP package, 'G8' = lead-free, RoHS-compliant finish with green mold compound. This matches the JEDEC 100-pin TQFP footprint shown in the datasheet pinout diagrams.
Does 71V3557S85BG8 support both linear and interleaved burst modes?
Yes, 71V3557S85BG8 supports both burst orders. The LBO (Linear Burst Order) pin selects mode: LBO = LOW enables linear sequence (0,1,2,3), LBO = HIGH enables interleaved (0,2,1,3). This is confirmed in the Functional Block Diagram and Interleaved/Linear Burst Sequence Tables in the datasheet.
Is JTAG boundary scan mandatory or optional on 71V3557S85BG8?
JTAG is optional but fully implemented on 71V3557S85BG8. Pins TMS, TDI, TCK, TDO, and optional TRST are present and functional per IEEE 1149.1. TRST may be left floating (internally pulled up) if not used; all other JTAG signals are required for scan operation.
How does the ZBT™ feature eliminate dead cycles in 71V3557S85BG8?
71V3557S85BG8 achieves ZBT™ by decoupling address/control registration from data transfer timing: a new read or write is initiated on one CLK edge, and associated data appears on the next edge-no idle cycles between successive accesses, unlike traditional pipelined SRAMs requiring turnaround wait states.
Can 71V3557S85BG8 operate with only two chip enables asserted?
Yes. The 71V3557S85BG8 requires CE1 = LOW, CE2 = LOW, and CE2 = HIGH for selection. Deselection occurs if *any* of those three conditions fails-e.g., CE1 = HIGH, CE2 = HIGH, or CE2 = LOW. This triple-enable scheme allows flexible bank selection and depth expansion without external gating logic.
71V3557S85BG8 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 119-BGA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM - Synchronous, SDR (ZBT)
- Memory Size:
- 4.5Mbit
- Memory Organization:
- 128K x 36
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- -
- Access Time:
- 8.5 ns
- Voltage - Supply:
- 3.135V ~ 3.465V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 119-PBGA (14x22)
71V3557S85BG8 FAQ
1.How can I place an order for 71V3557S85BG8 through Aetrix?
Please submit a Request for Quotation (RFQ) for 71V3557S85BG8 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 71V3557S85BG8 reliable?
The price and inventory of 71V3557S85BG8 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71V3557S85BG8 is usually 5 days.
3.What payment methods are accepted for 71V3557S85BG8?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71V3557S85BG8 transactions.
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4.How is shipping managed for 71V3557S85BG8?
71V3557S85BG8 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71V3557S85BG8 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 71V3557S85BG8?
For technical support, including 71V3557S85BG8 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71V3557S85BG8 requirements.
6.How does Aetrix verify that 71V3557S85BG8 is sourced from the original manufacturer or authorized distributors?
All 71V3557S85BG8 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 71V3557S85BG8 meets industry standards.
7.What is the process for return or replacement of 71V3557S85BG8?
All 71V3557S85BG8 units undergo pre-shipment inspection (PSI). If there is an issue with 71V3557S85BG8, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 71V3557S85BG8 part is unused and in its original packaging.
Return procedure for 71V3557S85BG8:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71V3557S85BG8 Tags
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M24C02-WMN6TP
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AT24C02C-XHM-T
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AT21CS01-STUM10-T
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24LC01BT-I/OT
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M24C02-FMC6TG
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AT24CS02-SSHM-T
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93LC46BT-I/OT
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AT24C04C-SSHM-T
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24LC01BT-I/SN
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24AA02UIDT-I/OT
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AT24C08C-STUM-T
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